ADAM'S SILURIAN

[Tidgy's Dad]

The other species of athyrid that I have from the Waldron Shale are the more usual smooth shelled forms that look more like terebratulids. Many of them, especially the larger forms, are often found broken or crushed, such is the result of being thin-shelled and unornamented. 

Judging by the size and general shape, I think this one is Meristina maria. 

[ClearLake]

Keep up the great work, Adam.  This seems like a nice diverse selection out of the Waldron.

[Tidgy's Dad]

3 hours ago, ClearLake said:

Keep up the great work, Adam.  This seems like a nice diverse selection out of the Waldron.

Thank you very much, Mike, my friend. 

Tis kind comments like this that help me continue with the project, plus the views these threads get, which is wonderful. 

I consider myself extremely fortunate to have been gifted so much diverse material by extraordinarily generous forum members that allows me to have a representative collection from so many formations and locations that I will never have the opportunity to visit.   

 

The athyrid Whitfieldella nitida seems to be very common in the Waldron Shale and similar aged formations in New York, but is quite unusual in Canada or Europe. It is smaller and more elongated  than Meristella, as well as being less flattened. Not terribly easy to photograph as they show almost no surface features.

 

Another specimen : 

And another :

Another :

Some of the tiny ones might be Nucleospira pisiformis, but I don't think so.

One more littl'un. 

Edited May 25, 2022 by Tidgy's Dad

[Tidgy's Dad]

There are three fairly common spiriferids found in the Waldron Shale. 

The largest is Eospirifer radiatus, seemingly the most common but easily distinguishable because of the size and its very fine costae. The species also occurs in the Much Wenlock Limestone of the UK and you can see my specimen on page 9 of this thread. 

The other two species have been more problematic with their naming. The smallest is Howellella crispa, but this seems to be a European only genus and so is often referred to in the literature as Howellella "crispa". It has sometimes been named Hedeina crispa, but this genus also seem to be restricted to Europe and Kazakhstan according to the Treatise. Though according to A. Williams et al. 2006, some of the USA forms belong to this genus. 

The medium-sized species is thus often listed as Hedeina eudora, though before this it was Eospirifer eudora, partly because a lot of early spiriferids were just placed in this, the earliest of spiriferid genera. Before that, of course, it was Spirifer eudora, but anything vaguely similar was placed in the "Spirifer" taxon back then.  

So, I think this is Hedeina eudora, I had to stop the prepping as bits started to flake off. It is 14 mm wide  :

Notice the beautiful fine growth lines :

The specimen above is the last of the Waldron brachiopods sent to me by @connorp, so thank you so much, they're wonderful. 

This fragment may also be a bit of a spiriferid. It doesn't seem to be a rhynchonellid as there does seem to be a remnant of a strophic hinge line ;

 

 

[Tidgy's Dad]

The phylum Brachiopoda is split into three subphyla, the Linguilformea and Craniiformea, informally known as 'inarticulates" and the Rhynchonelliformea, the " articulates". 

The Rhynchonelliformea is then split into a few classes; a couple of which are limited to the Cambrian, plus the Palaeozoic but minor class of the Chileata and the two well known classes, the Rhychonellata and the Strophomenata.

I think a lot of people are fairly familiar with the orders in the Rhynchonellata; Orthida, Rhynchonellida, Terebratulida, Spiriferida etc, but I don't think people are quite so familiar with the Strophomenate orders. I often hear people referring to productids, or their sub-order the chonetids, as strophomenids, but this is not accurate as the Strophomenida and the Productida are separate orders, so they should be referred to as strophomenates. The Billingsellida and Orthotetida are the other orders and should thus also be referred to as strophomenates and not strophomenids. 

Anyway, the strophomenids were the most successful order of brachiopods of all time, with over four hundred genera and some huge forms. But they are strangely rather few in number in the Waldron Shale. They had successfully adapted to muddy conditions as far back as the Ordovician, so it's a mystery to me why there are so few in this formation, they're reasonably abundant in the Much Wenlock Formation of the UK.  

When they do occur, the strophomenids include the largest species found in the Waldron. Leptaena,"rhomboidalis", probably better known as Leptaena waldronensis, seems to be the most common, we've seen them in shales before and they also occur in the limestones. The ubiquitous Leptaena is quite my favourite genus of brachiopod, but I don't have a Waldron specimen to show you, they seem comparatively thin-shelled here and are thus quite fragile. Strophonella, Protomegastrophia and Strophodonta are among other strophomenids that are sometimes found. 

 

What is more interesting is that one of the 'minor' orders of strophomenates occur heer; the Orthotetida are  represented by two species, the interesting three-lobed Triplesia putillus and the quite common, but rather flat and fragile, Fardenia subplana. This was incorrectly listed as Schuchertella subplana in some literature until very recently and the species was also previously known as Coolinia subplana. 

I am fortunate enough to have several nice bits, and as this is my earliest orthotetid, the order not becoming particularly common until the Carboniferous, I am doubly delighted. 

And even the reverse is nicely preserved ;

They are very thin :

You can see a very obvious and sudden growth line in the first couple of pictures above, but the species is also recognizable by little ridges on the costae that give each rib a look like a tentaculitid as evidenced particularly in the bottom right of the photo below. 

Another specimen : 

Bits of two individuals in this piece :

Fragments :

One can see the "tentaculitid ribs" more clearly in some of these :

Marvelous. 

 

 

[Tidgy's Dad]

I was hoping to find some microconchids, usually incorrectly referred to as "Serpula" in the literature, or a Cornulites proprius or two, but no luck so far, though I still have some hope. I thought I'd found a Tentaculites at one point, but closer examination leads me to think it's actually a bit of a very tiny crinoid. 

 

I always try to bear in mind preservation bias when I'm building up my little 'representative collections' from a formation. How many of the soft bodied organisms have left no trace? Also how many tiny organisms have I missed or are simply too small to be seen? And there's collecting bias and "what do I send to Adam?" bias. . 

 

But there seem to be relatively few molluscs found in the Waldron Shale, though I think the bivalves Pterinea brisa and Cypricardinia arata aren't too uncommon, they seem to be quite small and fragile and I wonder if the broken up pieces are often just assumed to be brachiopod fragments. 

 

Gastropods are represented by rare, high spired Loxonema and a few species of platyceratid. 

It seems that Platyostoma (was Platystoma) is the American version of Platyceras and that the two genera may be synonymous. One of the Waldron species seems to have been moved into the genus Naticonema and then back again while another was moved to Diaphorostoma and then to Strophostylus where it remains at the moment. (I think). 

I first tried telling these apart by looking at the size, shape, whether they had loose or tightly coiled whirls and whether they were more high-spired or not. This proved fairly hopeless as it turned out, as the species are quite variable in form. I should have guessed from the name. Platyostoma : 'platys', referring to flat or wide and 'stoma' meaning hole or mouth, so this was a reference to the apertures which is how the species are separated, at least in part. 

The most common species is Platyostoma niagarensis, which I expect are what most if not all of my specimens are. These have an inner lip fused to the body wall and thus difficult to spot as it is very thin. The aperture is quite rounded. The spire is depressed.  P. plebeium (not P. plebium which is incorrect) seems to be less tightly coiled and may have a space between the final whorl and the previous one. The aperture lip is slightly thickened and the aperture itself is more triangular. It has a more noticeable spire. Strophostylus cyclostomus is globose with a slightly elevated spire and oval to round aperture. The inner lip is thickened and angular to give an impression of the columella. This species was described by Hall in the 1881 Indiana Geological Survey on pages 316 to 317; Plate 31 Figure 13 :

Surface detail showing "the transverse striae of growth, and the finer revolving lines". 

I can't see this on my specimens, but maybe I need more magnification or better preservation. Makes sense as the name Strophostylus cyclostomus roughly translates to "straight-spikes round hole". 

 

This is my largest one and might possibly be Platyostoma plebium. It has a couple of really pretty bryozoan colonies growing on it. I know that these gastropods get much bigger, up to several centimetres across  :

Or does it show slight suggestion of the "spikes" or connecting lines between the faint striae, whch might make it Strophostylus cyclostomus? 

Beautiful bryozoan patterning :

You can see a bryozoan colony sticking out top left and the gastropod seems to have a more triangular aperture, so I'm leaning more towards P. plebeium again at this point: 

Comparatively high-spired :

Maybe someone with more experience and first-hand field experience can tell the difference for me? Thanks. 

The rest are probably Platyostoma niagarensis, I'll only show a few examples :

Low spired :

Another specimen :

And another :

One more, just because it's so tiny :

 

 

 

 

 

 

Edited May 28, 2022 by Tidgy's Dad

[Tidgy's Dad]

The most common cephalopod find seem to be Dawsonoceras, as is the case in the Much Wenlock Limestone Formation of the UK. 

But I guess they're reasonably uncommon, being the apex predator of the time. 

I found ancient listings for Gyroceras and Trochoceras too, though I think the latter is now limited to the Devonian so there may have been a name change. 

Here : 

I was so hopeful that this was a cyrtocone, it looks like it curves off in both directions, but looking at the ends, its actually rather flat and I think just a brachiopod fragment. 

Likewise, a little bigger :

But I think just a bit of shell; brachiopod or one of the elusive bivalves : 

This is something interesting though, tiny as it is. I'll pop along and put this in Fossil ID, I think. You never know your luck.

 

 

[Tidgy's Dad]

I have seen some really beautiful trilobites from the Waldron Shale and there seem to be quite a few species found there in varying degrees of rarity.

Maurotarion christyi seems to be one of the more common species and I had a bit of a cranidium from one identified by Scott @piranha at  the very bottom of page 11  in this thread. Here's another couple of photos :

I have some other fragments that may be trilobits. Or not. 

A genal spine ? 

And another ? 

Bit of a free cheek? (Very badly glued together.) 

In this close up it looks more like a bryozoan. Love the pyrite dots. 

A thoracic segment? 

Still, it's all great fun and I'm happy to have my oldest bit of an aulacopleurid. 

 

[Tidgy's Dad]

It was recently and quite reasonably suggested by the Kanny @Kane, that ostracods were one of the most undervalued and ignored fossil groups. 

I absolutely agree, though it's often quite hard to see the little beasties and I have difficulty telling them apart from each other and grains of sand. I recall reading somewhere that they are easily the most common arthropod fossils.

But I thought I'd even the score a teensy bit by posting one here, though I have previously posted a couple on my Ordovician thread and even a considerably more unknown phosphatocopid in my Cambrian one. 

I have posted quite a few pictures of my Waldron material here which have little ovalish objects that might be ostracods. Or might not be. 

But I'm fairly sure this is one. 

The Waldron species seem to be Leperditia faba and four species of what used to be Cornulina  sp. but is now known as Waldronites as Cornulina is now considered as a junior psynonym as the generic name had already been taken by a gastropod. (there are some nice Cornulina sp. snails pictured elsewhere on TFF). 

Dunno which one this is, but I think it's an example of one of 'em.

 

You can see where the two valves meet here :

This might be a slightly larger one.

Or not.

Another? 

 

 

Edited May 30, 2022 by Tidgy's Dad

[Tidgy's Dad]

I have found quite a lot of curved, calcite plates in my samples. Some are loose and others in the matrix. 

They are often quite plain and I was thinking athyrid, but the athyrids in the Waldron Shale seem to have rather thin shells and these are quite thick and chunky. Thank you to @TqB for suggesting crinoid calyx bits as these would fit nicely with Eucalyptocrinites crassus,I think. 

Other, quite similar bits seem to have tubercles or spine bases on them. Again, Tarquin's suggestion of crinoid calyx bits would match Eucalyptocrinites tuberculatus. 

Another lumpy one :

Or be shaped like an echinoderm plate?

The reverse :

Any help greatly appreciated. I'll try again in fossil id, too. 

 

 

Edited June 2, 2022 by Tidgy's Dad

[Tidgy's Dad]

The Waldron Shale is rightly well known for its beautifully preserved stemmed echinoderms, not just Eucalyptocrinites, but many other species of crinoid as well as blastoids and cystoids. 

Apart from the plates shown in the post above, my matrix samples contained lots of other bits, mostly stem columnals, I should imagine. 

Many of these are synostosial, which means they have no articulation on the face of the columnal and they have a simple round lumen in the centre. These could belong to Eucalyptocrinites, I think. 

Sometimes, they have symplectial articulation visible on the side of a quite smooth stem which suggests that there were perhaps ridges on the crenularium that have eroded away. 

Perhaps faint articulation on this one :

More rounded latus :

Maybe bits of calyx? 

Larger with a raised and rounded crenularium. 

[Tidgy's Dad]

Many of the flat, smooth ones also have flat, smooth sides to the stems. 

Many columnals are fully symplectial :

Or just around the edge :

Which produce zigzags on the sides of the stem :

[Top Trilo]

Wow those are small! Small but very interesting. Thanks Adam for highlighting some fossils that don't get as much attention as they should. I really enjoy going through your threads.

[Tidgy's Dad]

Yes, like ostracods and bryozoans, crinoid columnals are often neglected. I like this little article : "The Least Loved Fossils"

Crinoid Columnals.pdf

When someone is kind enough to send me a batch of fossils or matrix, I like to do justice to what I receive. 

Some of these ossicles are half a mm across, some a centimetre or more. 

Here are some heteromorphic stems with high nodal and lower internodal columnals : 

  

With a conspicuous crenularium. 

[Tidgy's Dad]

There are a small number with a pentagonal lumen and petaloid pits in the areola. 

More common are those with a petaloid lumen, sometimes synostosial or worn down : 

Sometimes symplectial : 

Bottom left shows one with a stellate lumen :

 

[Tidgy's Dad]

One lonely petaloid columnal : 

Several spiny ones :

I love this next specimen. 

I though it might be Tentaculites at first, but I can find little reference to them in the Waldron Shale other than really old mentions of T. inornatus and T. niagarensis from the Rochester Shale of New York which is of about the same age and has many species that also occur in the Waldron. However, I think t may actually be a really weird bit of echinoderm stalk. It's very tiny and I'm not sure if it tapers or not as the matrix covers part of it and is stubbornly refusing to come off. 

It seems to be solid rather than hollow.

I managed to dig it out a bit more. Maybe tapering? 

Edited June 4, 2022 by Tidgy's Dad

[Tidgy's Dad]

Holdfasts or the base of a small calyx? 

Another :

This looks like part of a Eucalyptocrinites holdfast with 'rootlet' cirri. 

And little bits that may be ossicles from the holdfast, cirri or brachials :

The joint where brachials branched? Mmm, there's a side branch too, so perhaps more likely another bit of holdfast: 

 

And this looks echinoderm, too :

 

Edited June 4, 2022 by Tidgy's Dad

[Tidgy's Dad]

I call this my mini-mortality plate as I think that there may be three aligned crinoid calyxes in this little piece of matrix. 

Not sure what species they are as there a lot of species present in the Waldron Shale. A couple of members have suggested Eucalyptocrinites sp. which is the most common genus in the Waldron and I think that its fellow monobathrid, Periechocrinus whitfieldi might also be a possibility. Note the base of a second calyx to the upper right of the main one :

Another calyx to the upper right of the first? 

And another directly below the first one :

 

Edited June 6, 2022 by Tidgy's Dad

[Tidgy's Dad]

That's it for now from the Waldron Shale, though I very much hope to add to this in the future. 

But before I finish the Wenlock I have one more species to display, a cystoid from the Osgood shale, which is a couple of million years older than the Waldron, though many genera and species seem to continue through the range. 

These are a couple of wonderful specimens of Holocystites scutellatus from Napoleon in Indiana, USA, kindly sent to me by the most excellent Ralph @Nimravis. Love them so much, my friend. 

A bit squashed :

The opening at the apex : 

Where the stem attached : 

The top, very badly preserved: 

Details of the tiny plates near to the base of the calyx : 

  

A single plate showing some of the pores that some have said were for respiration: 

This one shows some pyrite crystals:

The other specimen is more covered in matrix. I could remove some of it, but I quite like it with the lumps showing out /

You can see the thickness of the plates here, where they are broken off, still leaving an impression of the calyx plates on the cast underneath :

The top of the first specimen :

And where the stalk attached :

[Tidgy's Dad]

Halysites sp. 

Really nice piece of "Chain coral" from Orzechow in Northern Poland. Seemingly a Wenlockian specimen brought to the Polish beaches by glaciers. 

The genus was very successful and common in Silurian reefs. 

This one is part of the Sara the World Travelling Ceratopsian overburden and is from the brilliant @Kasia if I am not mistaken.  

 

[Kasia]

Correct again

[Tidgy's Dad]

On 8/17/2022 at 6:19 PM, Kasia said:

Correct again

Thanks to you I now have Halysites from Sweden and Poland! 

Despite having a fairly considerable Wenlock collection from the UK and USA, I don't have any from either country. They're quite common in the UK Much Wenlock Limestone, I just don( seem to have been lucky with this very interesting genus. 

 

[Tidgy's Dad]

I was very happy to recently acquire another fossil for my Much Wenlock Limestone Formation collection from the Wren's Nest, Dudley, West Midlands UK. 

Back on Page 5 of this thread, I posted this wormy looking thing and tentatively suggested it might be connecting tubes for the encrusting tabulate coral Aulopora. 

I was never very happy with this id and then wifey purchased me an encrusting coral for my birthday this year. 

The label is rather wrong, firstly as the coral it is growing on is not Favosites sp. but a little colony of Thecia swinderniana, see the top of Page 4 for a beautiful example of this coral. 

Secondly, Syringopora bifurcata is a phaceloid species, the correct designation for this specimen is Aulopora serpens. 

As you can see, t's nothing like the 'wormy thing', so my search for an if for that one continues................................

 

 

[Tidgy's Dad]

As is often the case, the underside of the Thecia swinderniana specimen shown above is covered in the encrusting cystoporid Fistulipora nummulina. 

F. nummulina is the most common species of bryozoan found in the Much Wenlock Limestone Formation, accounting for 24% of the bryozoans found according to a study by Owen published in 1969. I have posted this species several times in this thread, see Page 6 for some examples. 

The species often has monticules, domes or even gives rise to branches. Here some lumps are broken to reveal the beautiful internal structure showing the cystopores. 

 

[Tidgy's Dad]

A year on, another birthday, and wifey has added to my Much Wenlock Limestone collection once more with this wonderful partial crinoid and hash. 

I think that the label is incorrect as it is not what wifey ordered and looking at the seller's website, it seems that the specimen to which this label refers is still available. Wrong label sent! 

This specimen is really from the Wren's Nest, Dudley, West Midlands. And the crinoid should be Sagenocrinites expansus. 

I love these hash plates. There are so many species in a small rock. 

Tabulate corals : 

There's not too much on the reverse, but here's a beautiful, near complete little colony of Heliolites interstinctus. 

And a tiny bit of Favosites sp. 

And on the main surface, another Favosites sp. 

Not sure about this, I thought Halysites catenularius at first, but the openings are a little small, so it might be a bryozoan.

Edited October 4, 2023 by Tidgy's Dad